Means for diminishing, deadening, and preventing sound.



No. 740,081. PATENTED SEPT. 29, 1903.

H. w. BLAIR.

MEANS POR'DIMINI SHING, DEADENING, AND PREVENTING- SOUND.

- APPLICATION FILED arm. 29, '1896. RENEWED MAR. 7, 1903. no MKSDEL.

UNITE STATES Patented September 26, 1903.

HENRY w. BLAIR, or MANCHESTER, new HAMPSHIRE.

MEANS FOR DIMlNlSHlNG, DEADENING, AND PREVENTING SOUND.

SPECIFICATION forming part of Letterslatent No; 740,081, dated September 29, 1903.

Application filed September 29,1896. Renewed March 7, 1903. Serial No. 146,757. No medl.)

To all whom it may concern.-

Be it known that I, HENRY W. BLAIR, a citizen of the United States, residing at Manchester, in the county of Hillsboro and State of New Hampshire, have-invented certain new and useful Improvements in Methods and Means for Diminishing, Deadening, and Preventing Sound and theCause Thereof and for other Purposes; andI do hereby declare the following to be a full, clear, a'nd exact de-' scription of the invention, such as will enable others skilled in the artto which it appertains to make and use the same.

My invention relates to improvements in themethods and means for diminishing, deadening, and preventing sound, especially of machinery and for other purposes. In the present instance it is shown as applied to electric street-car motors merely for the purpose of showing one way in which it may be usefully employed.

I attain the foregoing results, as far as electric cars are concerned, by .the devices illustrated in the accompanying drawings, in which- Figure 1 is a longitudinal vertical section on line a; as, Fig. 2. Fig. 2 is atop plan view of a portion of the running-gear, showing my improvements, the trucks and axle-boxes being omitted. This figure also shows an envelop and connected air-pump operated by an eccentric carried on the same axle as bears the machinery. V

Similarletters refer tosimilar parts through-. out both views.

The letter A representsthe body of an electric car having any suitable construction of motor-gearing. Surrounding the motor is an envelop or covering B, having, if desired, a lining t' of lead or other substance which is a non-conductor of sound, If desired, there may be several envelops having air-chambers between them, from which the air may be partially or substantially wholly exhausted.

C is a valve to which an air-pump may be attached for the purpose of exhausting the air from the envelop or envelops B by hand, or the air may be exhausted by an automatic air-pump D and D',.connected to the axle E, to which is secured an eccentric F and F, or by the use of explosives, or by the condenhad to inspect the motor whenever desired.

The door 9 is provided with air-cushionsf, so that when closed it will fit snugly and be substantially air-tight. Y

The electric current enters through an insulated hole 0 in the usual way. It will be noticed that the covering B, which incloses the armature 9", commutator s, field-magnets u, and other parts connected to the electric motor proper, which cause the unpleasant sound so often heard when in operatiomalso protects the machine from dirt, dust, or accidental injury. By the exhaustion of the air from the envelop or envelops B no so und waves can proceed therefrom. There may be a stuffing-box v where the envelop surrounds the axle E'to prevent the ingress of air; .but any other means maybe employed for; the same purpose, 'The covering B maybe secured to or-snpported by the car or truck or axle in any suitable manner. I

I do not confine the application of my invention to street-cars actuated by electricity,

-In fact, my invention is of general application, and therefore I do not limit it to any special form of construction.

Having thus described my inventi on, what I claim is- 1. A casing inclosing machinery and means to exhaust the air therefrom operated by the inclosed machinery,substantiall y as set forth.

2. An envelop covering machinery and carrying an air-pump, and an eccentric connected with said pump and operated by an axle driven by said machinery.

3. An envelop covering machinery and carrying an air-pump to exhaust the air from said envelop in combination with an axle carrying said devices.

4. An envelop covering machinery and carrying an air-pump to exhaust the. air from said envelop in combination with an axle of a car carrying said devices and actuating means for operating said pump.

5. An envelop covering machinery carried by an axle, an air-pu mp and means driven by the axle for operating the pump to exhaust the air from the same, as set forth.

6. An envelop covering machinery and carrying an air-pump, in combination with a car axle carrying said devices, an eccentric for [5 exhausting the air from the envelop operated by the car-axle.

7. The combination of the axle of a car, an envelop covering machinery on said axle and carrying an air-pump, and means operated 20 by said axle to work the pump.

In testimony whereof I affix my signature in presence of two witnesses.

HENRY \V. BLAIR.

Witnesses:

H. P. HURST, O. M. BALL. 

